Strumigenys canina

Strumigenys canina

Strumigenys canina is a small predatory ant measuring 2-3mm, easily recognized by its relatively long narrow mandibles compared to other Strumigenys species. The fifth tooth from the base of the mandible is notably the longest and broadest, visible even when the mandibles are fully closed. This species belongs to the Strumigenys sauteri group and is one of the most common Strumigenys species in Hong Kong, where it has been collected from diverse habitats including roadsides, shrubland, tree plantations, bamboo forest, and secondary forests ^[1]. In Japan, it is considered rare but has been found in moist decaying wood within evergreen broadleaf forests ^[2]. The colony structure appears to be polygynous, with one sample containing 149 workers and 3 queens ^[1].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Native to East Asia including Japan, South Korea, mainland China (including Hainan, Hong Kong, Macau, Taiwan), and northern Vietnam. Found in primary and secondary forests, rubber plantations, and tree-lined areas from 29m up to 1000m elevation ^[1][3][4].
• Colony Type: Polygynous, colonies contain multiple queens. One documented colony had 3 queens along with 149 workers,24 alate gynes, and 1 male ^[1].
  • Colony: Polygyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 3-4mm based on genus Strumigenys patterns
  • Worker: 2-3mm ^[5]
  • Colony: At least 149 workers documented in a single colony, likely larger in established colonies ^[1]
  • Growth: Slow, Strumigenys are slow-growing ants
  • Development: Estimated 8-12 weeks based on genus patterns for short-mandibulate Strumigenys (Development is slow, colonies grow gradually. First workers (nanitics) will be smaller than mature workers.)
• Antkeeping:
  • Temperature: Keep at 22-26°C, this species prefers warm, stable conditions typical of its subtropical to tropical range. A gentle heating gradient allows ants to thermoregulate.
  • Humidity: High humidity required, aim for 70-85%. These ants come from moist forest environments and need consistently damp substrate. Keep the nest area noticeably humid.
  • Diapause: Likely no true diapause given the subtropical/tropical distribution, but may show reduced activity in cooler months. Maintain stable temperatures year-round.
  • Nesting: Prefers moist decaying wood in nature. In captivity, a naturalistic setup with damp soil/plaster works well, or a Y-tong nest with moisture chambers. Avoid dry conditions.
• Behavior: Strumigenys canina is a specialized predator that uses its short mandibles to capture small prey, primarily springtails and other micro-arthropods. Workers are slow-moving and forage individually. They are not aggressive and pose no threat to humans. Due to their tiny size, escape prevention is critical, use fine mesh barriers. The species exhibits unique behaviors including body smearing behavior documented by Masuko (1984).
• Common Issues: escape prevention is critical due to tiny 2-3mm size, they can slip through standard barriers, slow growth means colonies take months to establish, avoid overchecking or disturbing founding colonies, requires live prey (springtails), will not thrive on sugar alone or large prey items, high humidity is essential, dry conditions cause colony decline and death, wild-caught colonies may contain parasites that can devastate captive colonies

Housing and Nest Setup

Strumigenys canina requires high humidity and works well in naturalistic setups with damp substrate. A Y-tong (acrylic) nest with moisture chambers works well, or you can use a naturalistic setup with flat stones placed on damp soil. The key is maintaining consistently moist (but not waterlogged) conditions throughout the nest area. These ants naturally nest in moist decaying wood, so incorporating some rotten wood pieces into the setup mimics their natural environment. Because they are tiny (2-3mm), ensure all connections between the nest and outworld are narrow and use fine mesh on any barriers. A small water tube connected to the nest helps maintain humidity. ^[1][2]

Feeding and Diet

This species is a specialized predator that hunts small arthropods. In captivity, their primary food should be live springtails, these are the ideal prey item and what they would eat in the wild. Other small live prey like booklice, dust mites, and fruit flies may also be accepted. Strumigenys have short mandibles designed for precision hunting of tiny prey, so avoid offering large insects or chunks of protein. They do not typically scavenge and will ignore dead prey that is too large. Sugar sources are generally not accepted, these are strict predators. Feed small amounts of live prey every few days, removing any uneaten prey after 24 hours. ^[1]

Temperature and Care

Keep your colony at 22-26°C for optimal health and development. This species comes from warm subtropical to tropical regions in East Asia, so they do not tolerate cool temperatures. A heating cable on one side of the nest can create a temperature gradient, allowing the ants to choose their preferred zone. Room temperature within this range is acceptable. Avoid temperature fluctuations and keep the colony away from air conditioning vents or cold windows. Stable warmth is more important than exact temperature precision. ^[3][1]

Behavior and Temperament

Strumigenys canina workers are slow-moving and forage individually rather than in groups. They are not aggressive and will flee from disturbance rather than attack. The species is known for its unique 'body smearing behavior' documented in research. Workers have specialized glands that produce substances used in their hunting and possibly communication. Because they are so small, they are easily overlooked but are fascinating to watch when hunting. They pose no danger to humans and cannot sting. Their tiny size means they can escape through gaps that seem impossibly small, always use fine mesh (at least 0.3mm) for any barrier. ^[1][5]

Colony Development

Colonies appear to be polygynous, meaning they contain multiple queens. One documented colony had 3 queens along with 149 workers,24 alate gynes, and 1 male, suggesting this species naturally maintains multiple reproductive queens ^[1]. Growth is slow, Strumigenys are not fast-growing ants. A founding queen will take several months to produce her first workers (nanitics), and the colony will grow gradually from there. Be patient with founding colonies and avoid disturbing them too often. Queens areclaustral, meaning they seal themselves in a chamber and raise the first brood using stored fat reserves without leaving to forage.

Seasonal Care and Nuptial Flights

In Hong Kong, alates (reproductive males and females) have been collected via malaise trapping from mid-June to mid-July, suggesting nuptial flights occur during the summer months ^[1]. In Japan, colonies show activity year-round with workers collected in various months, though more frequently in warmer seasons ^[2]. Given their subtropical distribution, they likely do not require a true hibernation period. Maintain stable temperatures throughout the year and do not allow the nest to cool significantly in winter. The colony may show slightly reduced activity in cooler months but should remain active if kept warm.

Frequently Asked Questions

References